last day: Grebe, Sauer (etwas Seyfried) Flashcards
(30 cards)
Hormones, produced in the pituitary gland
Antidiuretic Hormone (ADH) = Vasopressin Increases the water permeability of the kidney collecting ducts (Sammelkanäle) --> Increased water resorption
Oxytocin
Stimulates milk secretion and uterus contraction
pituitary gland front lobe consist of
pitulary front lobe (with capillaries and endocrine cells) and
neutral pituitary
thyroid gland is filled with
thyroid gland follicle - colloid (enriched hormone structures)
thyroid gland produce
thyreoglobulin (only known ionidized biomolecule)
bind: TBG; Thyroxin-binding globulin
contraction of heart muscle - which structural components (proteins) do you need?
actin, binding tropomyosin, binding troponin (SU: TnT = Tropomyosin-binding subunit TnC = Ca2+-binding subunit TnI = inhibitory subunit) binding triggered by Ca2+
action potential (+20-+30 mV) How do we get there?
• K-permeability decreases with time & Na-permeability („funny current“) increases –> instabile resting potential
–> slow depolarisation (= pace maker potential)
• at threshold potential: voltage-gated Ca-channels open: Depolarisation
• Excitation transmission onto other cardiomyocytes via gap junctions
Excitation transmission heart
contractive wave starts in sinus knot (ca2+ triggered) –> atrioventricular knot (his bundle) –> tawara branches via purkinje fibers to chamber myocardium
resistance
Flow ungefähr 1/R
in blood vessels: L (length) and eta (viscosity of liquid) are constant, just r (vasoconstriction = Gefäßverengung) variabel
ateriols with varible radius
colloid osmotic pressure
osmotic pressure due to disolved proteins
Pressure is
highest in aorta and lowes in hohlvene
ER
- Discovered in 1945 in cells of chicken embryos
- Present in all eukaryotic cells
- It is an intracellular compartment: A lipid bilayer membrane enclosing an inner space (lumen)
- It is a network of interconnected membrane tubules and cisternae (“reticulum”) stretching across the entire cytoplasm (“endoplasmic”)
- It is the location where membrane proteins,
soluble cargo proteins and lipids are synthesized - From the ER, membrane proteins, soluble cargo
proteins and lipids are transported to other
compartments or to the extracellular space along
the secretory pathway
Protein quality controle by ER
unfolded –> URP (unfolded protein response) is released –> misfolded ERAD ER associated degedation pathway –> retrotranslocation (protein to cytosol and cleaved by 26S proteasome)
Golgi apparatus
- the Golgi was discovered by Italian physician Camillo Golgi (1897)
- it is the organelle where cell wall components, such as pectins and hemicellulose, are synthesized [cellulose instead is synthesized at the plasma membrane]
- it is the location where protein glycosylation continues (it starts in the ER)
The trans-Golgi network (TGN)
It is a tubular-vesicular organelle with a pleiomorphic shape (it has an undifined, irregular shape)
The trans-Golgi network (TGN) derives from the Golgi through the maturation of the cistearnae
Clathrin mediated endocytosis adaptors
LOLITA, T PLATE, AP-2 Complex, AtEH1, AtEH2, TM, TWd40-1, TWd40-2
Clathrin mediated endocytosis recruitment factors
TASH3, CAP1, AtECA4
Endocytosis
a cellular process in which substances are brought into the cell. The material to be internalized is surrounded by an area of cell membrane, which then buds off inside the cell to form a vesicle containing the ingested material. Endocytosis includes pinocytosis (cell drinking) and phagocytosis (cell eating). It is a form of active transport.
Secretion
is the movement of material from one point to another, e.g. secreted chemical substance from a cell or gland. In contrast, excretion, is the removal of certain substances or waste products from a cell or organism. The classical mechanism of cell secretion is via secretory portals at the cell plasma membrane called porosomes.[1] Porosomes are permanent cup-shaped lipoprotein structure at the cell plasma membrane, where secretory vesicles transiently dock and fuse to release intra-vesicular contents from the cell.
Animals: Lysosomes
small • unrelated to cell size • hydrolytic • low pH • main function is degradation
Vacuoles in plants
very large: 30 – 90% of cellular volume • energy efficient way to increase cell size • not always with hydrolytic activity • not always low pH • functionally diverse
How to degrade transmembrane proteins?
The Multivesicular Body/Prevacuolar Compartment
Bulding head groups of PIPs can be recognized by
lipid binding domains (LBDs)
Steps of Autophagy
Induction (Stress) –> Phagophore formation (first steps may occur at ER) –> Autophagosome with double membrane –> outer membrane – tonoplast fusion –> degradation
SCF Complexes and Protein Degradation
Ubiquitin: activation by E1
Ubiquitin is transfered to E2
Ubiqutinated E2 forms complex with E3 ligase and target
target ubiquitinated by E2/E3
target protein is degardated by 25S proteosom
SCF: Skp1/Cullin/F-Box
Nomenclature: SCFTIR1 : F-Box Protein is TIR1 Transport Inhibitor Resistant1